Accumulating evidence that anxiety and depression may be less distinct than previously thought has resulted in increased interest in the relationship between the two syndromes. Furthermore, comorbid presentations of anxiety and depression are particularly resistant to psychosocial and pharmacological interventions. Unfortunately our knowledge of the relationship between the two has been limited by a number of factors including a paucity of studies offering direct comparisons in clinical samples. a;so, despite the well-recognized heterogeneity of both anxiety and depression, most studies have employed samples of mixed anxiety and depressive disorders. In light of these difficulties, the proposed study will examine the interpersonal and cognitive functioning of clinically severe socially phobic and dysthymic individuals. Theoretical accounts and research evidence suggests these two disorders may have many common aspects despite distinct clinical presentations. For example, similar interpersonal and cognitive deficits are often the focus of interventions for the two disorders and are thought to be central in their etiology and maintenance. However, despite this similarity, few studies have compared the two groups. Furthermore, research suggests distinguishable subtypes of social phobia exist but little is known about how the subtypes differ from one another or from depressive disorders. This study will compare chronically depressed (dysthymic), social phobic (generalized and nongeneralized subtypes), and normal control subjects on cognitive, behavioral, physiological and self-report measures. Following a careful diagnostic screening, subjects will complete a battery of self-report measures of anxiety, depression and general psychopathology, participate in three brief roleplays (two interactions and a public speaking task) and complete two information processing tasks (a memory and an attention task). It is hypothesized that dysthymics' verbal and nonverbal behavior during the roleplays will be characterized by help-seeking and a negative affective tone, in contrast to generalized social phobics who are expected to adopt submissive, acquiescent strategies. Dysthymics are expected to devote excessive cognitive resources to processing negative information about themselves and to be overly concerned with failing to achieve their own internal standards of success. Social phobics, in contrast, are expected to demonstrate attentional and memory biases for information related to how others are evaluating them. Only nongeneralized social phobics are expected to experience excessive physiological arousal when public speaking. Results from the proposed study should increase our understanding of the cognitive and interpersonal aspects of both social phobia and dysthymia by identifying which aspects may be unique to the particular disorder (or to an anxiety versus a mood disorder) and which may be common to emotional disorders in general. Such information may suggest potential etiological variables which could be explored in future research. Also, these findings will be useful in refining psychosocial treatments for the two disorders and in the development of a treatment strategy for those who experience both social phobia and depression. The detailed examination of interpersonal behavior and cognitive functioning will be particularly useful for improving social skills and cognitive treatments, respectively.